1. Field of the Invention
The present invention relates to an automobile steering wheel provided with a communication system employing a light transmitting means.
2. Description of the Related Art
Lately, audio sets, drive computers or others have come to be incorporated in automobiles, therefore control switches have come to be disposed on pad portions of steering wheels.
In this case, multiplex communication circuits using light communication means are publicly known as communication systems between pad portions and column portions of steering wheels, wherein light emitting units are disposed on pad portions while light receiving units on column portions.
Such a communication system as this is provided, as shown in FIG. 23, with a switch 30, a transmitting side remote control IC 31, a driver circuit 32 and a power circuit 33 on a pad portion 16.
A signal relay portion M is provided with a light emitting circuit 34, a light receiving circuit 35 and a signal regeneration circuit 36. Further, a waveform shaping circuit 37, a receiving side remote control IC 38, an output interface 39 and a power circuit 40 are disposed on a column portion 18. Moreover, a power relay portion 41 is disposed between the pad portion 16 and the column portion 18.
Through the operation of the switch 30 on the pad portion 16, the emitting side remote control IC 31 is activated being power supplied by the power circuit 33, thereby a plurality of electric signals are serialized.
Next, the series signal is amplified in the driver circuit 32 and a light signal is emitted from the light emitting circuit 34 based on said series signal. On the other hand, said light signal is received in the light receiving circuit 35, said light signal being converted again in a signal regeneration circuit 36 to an electric signal. And, said electric signal is shaped to the former pulse waveform in a waveform shaping circuit 37. Subsequently, said pulse waveform is transmitted to an output interface 39 through the intermediary of a receiving side remote control IC 38 to drive electric appliances and actuators.
These communication systems, however, require the multiplex communication circuits, causing the systems to be complicated and the costs to be high.